Methods: Reflective spheres were placed on the skin over the joints of the right pelvic limb of seven adult, hound-type dogs with no clinical signs of orthopaedic or neurologic disease. Five trials of stair and ramp descent of each dog were recorded using four 60 Hz digital infrared cameras. Two-dimensional kinematic data were collected as dogs walked down stairs and on a continuous decline of equivalent slope. Maximum and minimum joint angles and ROM were calculated for the coxofemoral, femorotibial and tibiotarsal joints.

Results: Stair descent resulted in significantly greater femorotibial flexion and tibiotarsal flexion and extension compared with continuous slope descent. Significantly greater ROM was achieved in the coxofemoral, femorotibial and tibiotarsal joints during stair descent.

Clinical Significance: Compared with a continuous slope, stair descent achieves greater ROM in the pelvic limbs of dogs. Stair descent may be a useful therapeutic exercise to improve ROM in dogs with musculoskeletal disease of the pelvic limb, and ramp descent may be easier for dogs with limited motion of pelvic limb joints.

DOI: 10.1111/j.1748-5827.2010.00956.x

DOI: http://dx.doi.org/10.3415/VCOT-10-03-0038

ANIMALS: 8 mature dogs.

PROCEDURE: A 3-mm ostectomy of the mid portion of the radius was performed in all dogs. Implants designed to release STH at a rate of 4 mg/d were placed SC in 4 dogs (treated group [STHG]), and another 4 dogs received no implants (control group [CG]). Serum concentrations of STH, insulin-like growth factor I, and osteocalcin were determined before surgery, and weekly for 8 weeks. Scintigraphic evaluation of the ostectomy sites was performed before surgery, and at weeks 2, 4, 6, and 8 after surgery. Histologic evaluation ofthe ostectomy sites was performed at the conclusion of the study at week 8.

RESULTS: Significant (P < 0.05) increases in serum STH, insulin-like growth factor I, and osteocalcin concentrations were observed in dogs of the STHG during the 8-week study period. Scintigraphic activity of the ostectomy sites was increased in dogs of both groups, but dogs of the STHG had significantly (P < 0.05) greater activity, compared with dogs of the CG. Coalescence of nuclear activity across the ostectomy site was observed in dogs of the STHG, whereas dogs of the CG maintained 2 distinct areas of metabolic activity. Histologically, dogs of the STHG had bridging calluses with areas of endochondral ossification and ongoing osteogenic activity, whereas dogs of the CG had nonossified fibrocartilage typical of nonunion fractures.

CONCLUSION: Using the ostectomy gap model, recombinant canine STH enhanced the metabolic and histologic aspects of bone healing in dogs.

Study Design—The depth of the DFE was related to the radiographic thickness of the patella in this experimental study.

Animals or Sample Population—Twenty immature canine cadavers.

Methods—Patella thicknesses were measured from lateral radiographs. Actual DFE depths were determined for pins driven in normograde fashion and for pins driven retrograde from the central depression between the metaphyseal pegs and from the cranial pegs. The association of DFE depth and patella thickness was evaluated using linear regression analysis. Using 95% confidence intervals, rules for estimating the safe depth of implant placement into the DFE were determined.

Results—DFE depth had significant correlation with patella thickness for pins placed in retrograde fashion from the central depression between the metaphyseal pegs (r²= .83) and from the cranial pegs (r²= .82) and for pins placed in normograde fashion (r²= .65).

Conclusions—Based on 95% confidence intervals, pins placed in retrograde fashion from the central depression between the metaphyseal pegs may be safely driven into the DFE a distance equal to 140% of patella thickness. Pins placed from the cranial metaphyseal pegs may be driven to a depth equal to 80% of patella thickness, and pins placed in normograde fashion may be driven to a depth equal to 30% of patella thickness.

Clinical Relevance—Measurement of patella thickness assists the surgeon in determining the approximate depth that pins may be driven into the DFE without penetrating the articular surface of the stifle joint.

Study Design—Relationships were determined between the depth of the proximal femoral epiphysis (PFE) and the contralateral PFE, and the PFE and pubic bone width.

Animals or Sample Population—20 immature dog cadavers.

Methods—Actual PFE depths were determined at the center of the physeal surface and at four other eccentric points. The contralateral intact PFE depth and the width of the cranial aspect of the pubic bone were measured from radiographs.

Results—Mean ratios of actual central PFE depth to radiographically measured (1) contralateral PFE depth and (2) pubic bone width were 1.04:1 and 1.09:1, and ratios of actual eccentric PFE depths were 0.89:1 and 0.93:1. Body weight was not useful in estimating depth of the PFE.

Conclusions—For the central epiphysis, pins may safely be placed a distance equal to 75% to 80% of the contralateral intact PFE depth or pubic bone width, measured from a ventrodorsal radiograph, with minimal risk of penetration through the articular surface. Pins placed eccentrically may be safely driven a depth equal to 65% of the radiographically measured contralateral intact PFE depth or pubic bone width.

Clinical Relevance—Estimating the safe depth of implant placement into the PFE avoids penetration of the articular surface.

Study Design—After an ostectomy of the midshaft radius, bone healing was evaluated over an 8–week period in control dogs (n = 4) and dogs receiving recombinant canine STH (n = 4).

Animals or Sample Population—Eight sexually intact female Beagle dogs, 4 to 5 years old. Methods—Bone healing was evaluated by qualitative and quantitative evaluation of serial radiographs every 2 weeks. Terminal dual-energy x-ray absorptiometry and three-point bending biomechanical testing were also performed.

Results—Dogs receiving STH had more advanced radiographic healing of ostectomy sites. Bone area, bone mineral content, and bone density were two to five times greater at the ostectomy sites of treated dogs. Ultimate load at failure and stiffness were three and five times greater in dogs receiving STH.

Conclusions—Using the ostectomy gap model, recombinant canine STH enhanced the radiographic, densitometric, and biomechanical aspects of bone healing in dogs. Clinical Relevance—Dogs at risk for delayed healing of fractures may benefit from treatment with recombinant canine STH.

Study Design— A prospective, randomized, experimental study.

Animals— Ten mixed-breed research dogs.

Methods— Two US treatments, one at an intensity of 1.0 W/cm² and one at 1.5 W/cm², were administered to the caudal thigh region of 10 adult male and female hound-type dogs weighing 20.5 to 25.0 kg. Needle thermistors were inserted in the caudal thigh muscles below the skin surface at depths of 1.0, 2.0, and 3.0 cm, directly under the US treatment area. Both intensities of US treatment were performed on each dog over a 10-cm² area for 10 minutes using a sound head with an effective radiating area of 5 cm². Treatments were administered in random order. Tissue temperature was measured before, during, and after US treatment until tissue temperature returned to baseline.

Results— At the completion of the 10-minute US treatment, the temperature rise at an intensity of 1.0 W/cm² was 3.0°C at the 1.0-cm depth, 2.3°C at 2.0-cm depth, and 1.6°C at 3.0-cm depth. At an intensity of 1.5 W/cm², temperatures rose 4.6°C at the 1.0-cm depth, 3.6°C at 2.0-cm depth, and 2.4°C at 3.0-cm depth. Tissue temperatures returned to baseline within 10 minutes or sooner after treatment in all dogs. Conclusions— This study demonstrates that significant heating occurs in the superficial thigh muscle of dogs during 3.3-MHz US. Clinical Relevance— 3.3-MHz US can be used to increase superficial tissue temperature in dogs, although the amount of time that tissue temperature remains elevated is relatively short.